Abstract: Objective To understand the risk factors of breast cancer in females and provide evidence for the prevention and control of breast cancer. Methods Matched pairs case control study was conducted on the exposure information of newly diagnosed breast cancer cases in our hospital from January 2005 to June 2008. The data were entered with EpiData and analyzed with SPSS. The signal variate and multivariate analysis on breast cancer risk factors were conducted with logistic regression model Results Multivariate analysis indicated that irregular menses (OR= 10.66), external injury history of breast (OR=10.87), lump in breast (OR=7.69), serious mental stress (OR=13.16) and frequent garlic eating (OR=0.42) were associated with the incidence of breast cancer. Conclusion The breast cancer risk factors in females in Pinghu mainly included irregular menses, external injury history of breast, lump in breast and serious mental stress, but frequent garlic eating was protective factor. It is necessary to strengthen the nutrition guidance and physical exercise and keep active mental status and health life style for the effective prevention and control of breast cancer.